Punctures of the spinal area are required in conjunction with a variety of medical and surgical procedures. Frequently medication, and in particular, epidural and spinal anesthetics must be introduced through a needle or a catheter. It may be desirable to both introduce medication in the vicinity of the puncture through a spinal needle and to introduce medication through a catheter to a location remote from the puncture in the epidural or spinal spaces.
Using prior art techniques, multiple punctures would have to be made for simultaneous introduction of an epidural catheter and a spinal needle, or for the introduction of two epidural and/or spinal catheters. Multiple spinal punctures have greater risk than a single puncture because of the increased trauma from additional punctures and because the time required to perform the procedure must be extended.
Spinal anesthesia frequently requires the initial administration of small quantities of an anesthetic agent into the subarachiod space. Since spinal anesthesia may be effective for only short periods of time, an adjunctive epidural anesthetic technique that can be continuous may be required for longer surgical procedures. Alternatively, either continuous epidural or spinal techniques must be utilized. The epidural technique yields a less dense local anesthetic block, while the spinal technique can lead to equally undesirable consequences including post spinal headache. Significant advantages could be obtained if the epidural and spinal procedures could be combined.
A procedure using conventional prior art single lumen needles to administer the spinal and epidural anesthetic requires the procedures either be performed at separate sites, or the two procedures be separated by a time interval. It would be advantageous and would reduce trauma if both procedures could be carried out nearly simultaneously at the same site utilizing small gauge spinal needles. If both procedures were carried out simultaneously utilizing one puncture the length of the procedure, and the discomfort to the patient would be reduced.
One option for using a single needle is to use a needle to locate the epidural space and then to insert a spinal needle through the needle to such an extent that the spinal needle penetrates the dura. An anesthetic agent can then be administered through the spinal needle. The spinal needle can then be withdrawn, leaving the needle in position for use in introduction of an epidural catheter in the usual way. This technique may have a significant risk in that the epidural catheter will pass into the space through the perforation and be undetected. Also the immediate epidural catheterization is not assured.
If a single needle is not used for the administration of the spinal and epidural anesthetic, but rather multiple needles are used, multiple punctures must be made in separate locations. One puncture is used for the insertion of, and to guide the spinal needle while the other puncture is used for the introduction of a catheter or for the introduction of a second needle.
If combined spinal and epidural anesthesia is to be used, the time to complete the epidural must be minimized once the spinal anesthetic is injected since a dangerous situation may occur such as serious drops in blood pressure and/or pulse rate once the spinal anesthetic has been administered. This dangerous situation may arise during performance of the epidural catheterization since using prior art techniques epidural catheterization must be performed subsequent to the spinal anesthetic injection unless multiple needles and multiple punctures are used.
The above mentioned problems have been largely over come by an epidural-spinal needle which is disclosed and claimed in U.S. patent application No. 07/072,428. The epidural-spinal needle is a dual lumen needle having lumen of different gauges. The larger lumen is sized to pass a catheter and configured to direct a catheter into and along the epidural space. The smaller lumen serves as an introducer for a fine gauge spinal needle. The purpose of the introducer is to assure that the fine gauge spinal needle passes into the epidural space without being bent or fractured by bone and tissue matter which it must pass through before entering the epidural space.
The epidural-spinal needle serves to locate and cannulate the epidural space, introduce a spinal needle into the epidural space, introduce a spinal or epidural catheter, or the introduction of multiple catheters through a single puncture resolving many of the problems of the earlier needles. It will allow for the simultaneous introduction of one or more needles, a needle and a catheter, or multiple catheters through a single skin puncture. Thus the epidural-spinal needle has advantages with respect to the prior art by reducing trauma, reducing procedure time, and providing the practitioner with a greater flexibility regarding the positioning of the catheters and needles for a specific procedure since the needle of the present invention can function as an introducer.
The present invention provides a method for making the epidural-spinal needle of the U.S. application No. 07/072,428 as well as an improved tip and stock configuration for an epidural-spinal needle.
The tip configuration of the present application further reduces the trauma of insertion of an epidural-spinal needle, guides the spinal needle into the epidural space without obstruction from bone or tissue, and directs a spinal needle into the dura at an angle. Having a skewed path through the dura wall assists the sealing of the wall when the needle is removed and in this manner further reduces the chance of dural headaches.
The improved stock provides reference surfaces for aligning the catheter and spinal needle to aid in the insertion of the catheter and spinal needle; additional grips for holding and inserting the spinal needle; and means for holding catheters during insertion of the spinal needle.